India, July 26 -- It was April 1, 2019, just another All Fools' Day in our strange world.

Algerian president Abdelaziz Bouteflika faced massive protests after nearly 20 years in power; actor Felicity Huffman pleaded guilty in a varsity cheating scandal; British parliament voted against four Brexit alternatives; and a US judge rejected a plan by Donald Trump (in his first term) to send asylum-seekers to Mexico.

Amid this global churning, in the Mediterranean port city of Alicante, two teenagers faced each other for the first time in the opening round of a nondescript Challenger tennis tournament.

From Sexten, Italy: Jannik Sinner, 17. From Murcia, Spain: Carlos Alcaraz, 15.

The world did not know it then, but the encounter would mark t...